The U.P.P.E.R. is at the top end of Open Cycles’ line of refined and versatile gravel-bike frames. It’s lighter than the classic U.P. (which stands for Unbeaten Path). It can run 700c wheels with tires as wide as 40 mm and even 27.5" hoops with 2.1" mountain bike tires. How can the frame handle that? The difference in the radius between those two tire-and-wheel combinations is a mere 8 mm. The U.P.P.E.R. frame and its U-turn fork take flat-mount calipers. With the Multistop design, you can run whatever drivetrain you want: 2 x 10/11, 1 x 10/11 and Di2. The hardest part will be planning your U.P.P.E.R. build.